Adjustable retarding device for reciprocating valves.



PATBNTED 00T. 11, *1904.`

l H. P. THOMPSON. ADJUSTABLE RETARDING DEVICE POR RECIPROCATINGrlVALVES.'

APPLIOATION FILED NOV. `19, 1903.

3 SHEETS-SHEET 12 N0 MODEL.

PATENTED 00T. 11, 1904.

l H fP. THOMPSON. ADJUSTABLE EETAEDING DEVICE E oE-EEQI-PROGATINGVALVES.

APPLICATION FILED NOV. 19, 1903.

3 SHEETS-SHEET 2.

N0 MODEL.

PATENTED OCT. 1l, 1904-..

E. E. THOMPSON. i ADJUSTABLE EETAEDING DEVISE EOE EEGIEEUGATING VALVES.

APPLICATION FILED NOV.19, 1903.

3 SHEETS-SHEET 3.

.N0 MODEL.

,WW @SNN 1 ww UNITED STATES Patented october 11, 1904.

HUGH PERRONET THOMPSON, OF CHICAGO, ILLINOIS.

ADJUSTABLE RETARDING DEVICE FOR RECIPROCATING VALVES.

SPECIFICATION forming part of Letters Patent No. 772,115, dated October11, 1904. Application filed November 19,1903. Serial No. 181,761. (Nomodel.)

[o @ZZ whom t may concern:

Be it known that I, HUGH PERRONET THOMP- SON, of Chicago, in the countyof Cook and State of Illinois, have invented certain new and usefulImprovements in Adjustable Retarding Devices for Reciprocating Valves;and I hereby declare that the following is a full, clear, and exactdescription thereof, reference being had to the accompanying drawings,which form part of this specification.

My invention relates to adjustable retarding devices for reciprocatingvalves.

In the use of mechanism such as pneumatic sewage-ejectors and the likewherein is employed a valve which acts as a combined pressure andexhaust valve, serving to control the pressure within the workingchamber, disadvantageous results are found to follow from unduly-rapidmovements of the reciprocating controlling-valves, such results-forexample, the slamming of the ejector checkvalves in the case of asewage-ejector-being occasioned by the sudden reversal of pressureconditions within the cylinder due to such rapid alteration of theposition of the controlling-valve.

The primary object of my invention is to provide a retarding device forreciprocating valves-such, for instance, as that above described-whichshall -prevent unduly-rapid movement of the valves in reversing thepressure conditions in the devices controlled thereby and which shall beefficient and advantageous in use.

More particularly, an object of my invention is to provide such yaretarding device which will be capable of ready adjustment to vary'thedegree of resistance interposed by it to the movement of thecontrolling-valve in either direction.

A further object of my invention is to provide a retarding device of thecharacter described the resistance of which to the movement of thecontrolling-valve in opposite directions may be independently varied.

A still further object of my invention is to provide a retarding deviceof the character described which shall offer different resistancesduring different portions of its excursion and shall effect its maximumretarding action only while the valve is traveling within the criticallimits of its throw-that is to say, within that portion of its excursionduring which it initially effects the reversal of the pressureconditions in the associated devices.

A yet further object of my invention is to provide a practical, simple,and efficient dashpot mechanism adapted for this and other uses.

In the drawings I have illustrated my invention as embodied in astructure associated with a valve such as that employed as apressure-controlling' valve in conjunction with pneumaticsewage-ejectors in the well-known Shone system of sewage disposition.

In said drawings, Figure 1 is a top plan view, partly broken away, of apressure-controlling valve equipped with retarding devices embodying myinvention. Fig. 2 is al longitudinal vertical section therethrough,illustrating the mechanism in the position assumed when theexhaust-ports of the controllingvalve are opened to the devicescontrolled thereby. Fig. 3 is a similar view illustrating the positionassumed by the parts when the controlling-valve is in transit to openthe pressure-ports to the devices controlled by the valve. Fig. 4 is asimilar view illustrating the position of the parts when thecontrolling-valve has completed its transit and the pressure-ports areopened. Fig. 5 is an enlarged view, in longitudinal vertical section, ofthe retarding devices. Fig. 6 is a transverse vertical section on line 66 of Fig. 5.

Throughout the drawings like numerals of reference refer to like parts.

10 indicates generally the casing of a controlling-valve suitablyconstructed and comprising generally a cylindrical chamber A11, twoannular separated chambers 12 and 13, associated with the respectiveends of the cylinder 11, and a chamber 14 for, a D-valve, to bedescribed. y

15 and 16 indicate, respectively, pressure and exhaust pipe connectionscommunicating, respectively, with the annular chambers 12 and 13.

17 and 18, respectively, indicate series of ports connecting the annularchambers 12 and 13, respectively, with the corresponding ends of thevalve-chamber 11.

19 indicates a piping-orifice designed for connection with the deviceswhose pressuresupply is to be controlled.

2O indicates a constantly-open port connecting the annular chamber 12 tothe D-valvecontaining chamber 14.

21 indicates a port extending from the chamber 13 to the surface of thechamber 14.

22 andr23, respectively, indicate conduits establishing communicationbetween the extreme ends of the main valve-chamber 11 and the surface ofthe chamber 14.

24 indicates a D -valve mounted in the chamber 14 and provided with apassage 25, extending therethrough. One'exterior orilice 25 of saidpassage is extended, so that it constantly covers the port 21 and iscapable, as indicated in Fig. 2, of also covering the oriiic'e ofconduit 23. The opposite end of the passage 25 isso disposed that whenthe valve is in the position illustrated in Fig. 3 it registers with theorifice of conduit 22.

26 indicates a valve-lever arm for controlling the movement of theD-valve 24, carried by a rock-shaft 27, to be operated by suitablemechanism not necessary herein to describe.

28 indicates generally the reciprocating member of the main orcontrolling valve, which comprises, essentially, two heads 29 and 30,mounted upon a common shaft, as shown. These heads 29 and 30 are-spacedapart a less distance than that separating' the ports 17 and 18, so thatsaid ports may be simultaneously covered by the valve-heads, asindicated in Fig. 3, and the heads are so proportioned that when eitherhead reaches such position as to uncover the corresponding ports 17 or18 the other head closes its corresponding ports, as illustrated inFigs.2 and 4.

The operation of the parts thus described will be as follows: Assumingthat the parts are in the position shown in Fig. 2, it will be obviousthat air under pressure in the pipe 15 can find no ingress into the pipe19, as the ports' 17 are closed by the valve-head 29. On the'other hand,however, the pipe 19 is in open communication through ports 18 andannular chamber 13 with the exhaust-pipe 16, so that air may escapethrough pipe 19 from the devicesWith which it communicates. It isnoticedthat in this position the D-valve 24 is at its' extreme limit ofmovement to the right, and under such conditions pressure within thepipe 15 is communicated through the annular chamber 12, port 20, chamber14, and conduit 22 to the left face of the piston-head 29, tending tohold it in position. (Illustrated in Fig. 2.) On the other hand, theconduit 23, communicating' with the opposite end of the valvechamber 11,opens into the D-valve orifice 25', lwhich constantly communicates withthe annular exhaust-chamber 13 through the port 21. If now by theoperation of suitable exy traneous mechanisms the D valve 24 be thrownto the limit of its movement to the left, the conditions of pressureupon opposite ends of the member 28 will be reversed. Now the pressureconstantlyr exerted in chamber 14 is communicated to the conduit 23 andacts upon the right end of the valve, while the left end, communicatingthrough the conduit 22 and D-valve passage 25 with the exhaustchamber13, is no longer under pressure. Consequently the valve is forced to theleft until it reaches the position shown in Fig. 4, where it will remainuntil the return of the D-valve 24 to its original position to restorethe pressure conditions first described. In its movement from right toleft it will be noted that before the valveahead 29 uncovers the ports17 the valve-head 30 covers its corresponding ports 18, therebydisconnecting the pipe 19 from both the pressure and exhaust sides ofthe exterior piping. Continued movement of the valve, however,subsequently opens the ports 17 to the chamber 11,while maintaining theports 18 closed, thereby establishing connection between thepressure-pipe 15 and the pipe 19 through the intermediary of the annularchamber 12 and its ports 17 and the valve-chamber 11, as will be clearlyapparent from an inspection of Fig. 4.

The parts thus far described constitute a valve construction well knownin the art.

At one end of the valve-casing 10, in axial alinement with the chamber11, I provide a casing 31 for my retarding device of suitableconliguration and construction to provide a reservoir-chamber 32 and adash-pot cylinder 33.

34 indicates a closure of an opening in the top of the reservoir 32, and35 indicates a suitable turn-cock at the bottom for draining thereservoir.

36 indicates a stem extending through the reservoir and axially into thedash-pot cylinder 33 at one end and at its other end suitably connected,as by a joint 37, with the valve-head 30. v

38 indicates a dash -pot piston arranged within the cylinder 33 andarranged to slide upon the end of stem 36 between two suitablyseparatedstop-abutments 39 and 39, carried by said stem. At its opposite endsthe'cylinder 33 is provided with circumferential 4recesses 40 and 40',with Which respectively communicate series of relatively-shortlongitudinally-extending grooves or channels 41 41,designed toconstitute by-pass ways around the piston. Intermediate the recesses 41and 41 of the cylinder 33 is left an'unbroken cylindrical portion 42,with which the dash-pot piston 38 is adapted to make a close fit. Aby-pass is also provided between the 'circumferential recesses 40 and 40by radial openings 43 and 43 from the recesses 40 and 40", respectively,and a longitudinal connecting- TOO duct 44. Such 'communication betweenthe opposite ends ot' the cylinder 33 is, however, controlled by valves,which I will now describe. At the point of intersection of the duct 44with each of the openings 43 and 43 is arranged an adjustable valveadapted to control the passage of liquid from the corresponding end ofthe cylinder 33 into the duct 44.

These two valves are exactly alike in their construction, and I willtherefore describe only valve 45 controlling the opening 43, it beingunderstood, however, that the valve 45', controlling the opening43, isof exactly similar construction.

46 indicates a plug overlying` the opening 43 and provided at its outerend With a beveled valve-seat 47.

48 indicates a constantly-open passage extending through the plug 46radially of the cylinder 33. i

49 indicates an enlargement of the duct 44 surrounding the upper portionof the plug 46.

50 indicates a coacting valve element threaded Jfor adjustment into thecasing 31 in registration with the plug 46 and provided in its lowerface with a deep recess 51, having its lower annular edge beveled, as at52, to coact with the seat 47 of the plug 46.

53 indicates a check-nutfor locking the valve member 50 in adjustedpositions.

Obviously the adjustment oi' themovable member 50 toward and from theplug 46 varies the size of the opening between the valvesurfaces 47 and52, and so regulates the flow oi' liquid from the recess 40 into theduct 44. I also provide in my valve means for permitting the i'low ofliquid from the duct 44 into the recess 40 not controlled by the valvemember 50. This'means comprises generally a passage around theadjustable member controlled by a check-valve opening to permit theiniiow of liquid practically without resistance.

In the specific construction shown, 54 indicates a transverse passagethrough the plug 46 from the duct enlargement 49 to the-center of theplug. 55 indicatesa central passage from said passage 54 to the outerface of the plug 46. The outlet of the passage 55 is shaped to afford aseat for a small check-valve, preferably a ball 56, caged in the recess51 of the movable valve member 50. It will be apparent that inloWingliquids may pass from the duct 44 through its enlargement 49 and thepassages 54 and 55, raising the ball-valve 56, and then flowing downthrough the passages 48 without passing through the adjusted openingbetween the coacting valve-faces 47 and 52, so that the valve 45,considered as a Whole, acts only to control the flow of liquid in onedirection and constitutes practically a check-valve having an adjustableby-pass. It will also be clear that the iiow of the liquid of thedash-pot in the opposite direction is controlled by the valve 45/ andmay be regulated to a rate entirely different from that of its iow fromthe left side of the piston to the right. This is of course because theinflow of the liquid to either side of the piston is practicallyunobstructed through the operation of the check-valves 56 56', while itsoutflow from each end is independently regulated by adjustment of thecorresponding valve member 50 or 50. It will be apparent that theopposite ends of the dash-pot cylinder 33 might not be adapted to holdexactly the same quantity of oil by reason of the introduction of thestem 36 into the left end of the dashpot Without the provision of acorresponding part in the right end. To provide for this variation andalso to maintain in available position a constant supply of the liquidto compensate for leakage or loss through other causes, theliquid-reservoir 32 is arranged in communication with the duct 44 by asuitable channel 57, as best illustrated in Fig. 5.

The use and operation of a device constructed as herein set forth willbe as follows: Assuming that the D-valve yof the controllingvalvemechanism be operated to throw the controlling-valve 28 from theposition illustrated in Fig. 2 to that illustrated in Fig. 4, asheretofore described, the rst part ofthe movement of the valve 28 meetswith substantially no resistance from the retarding mechanism, as thelost-motion connection of the dash-pot piston 38 with its stem 36permits an initial movement of the stem relative to the piston Withoutchange of position of the latter. When, however, the abutment 39 comesinto contact with the piston 38, the piston begins its travel to theleft, at first interposing comparatively little resistance to themovement of the controlling-valve, as the liquid within the dash-potpasses around the piston through the by-pass ,ways 41. It will be notedthat while this condition exists within the dash-pot the main valve-head3() is traveling over ports 18 to cut them oli from pipe 19 while thevalve-head 29 is yet entirelyclosing the ports 17. When now the partsreach the position illustrated in Fig. 3, the piston cuts oli' theby-pass ways 41 and exerts its IOO greatest resistance `to furthermovement, as

the only passage around the piston 'is now through the regulable valve45, the passage 44, and back through the check-valve 56 of valve 45 tothe right side of the piston. During this period it will be noted thatboth the pressure-ports 17 and the exhaust-ports 18 of thecontrolling-valve are closed and that the proportions of the dash-potconstruction are such that the dash-pot piston will offer its greatestresistance until the head 29 of' the controlling-valve has partiallyopened the pressure-port 17 to pipe 19. Consequently the port 17, beingopened as slowly as desired, the pressure is applied to the pipe 19 andthe mechanism associated therewith gradually. When now the ports 17 aresufficiently opened and the dash-pot piston has traveled suchdiscursion.

tance that its right edge passes the right ends of the by-pass grooves41, the action of the dash-pot is accelerated by the increased rapidityof the iow of liquid escaping from the left side thereof to the right bythe said bypass grooves 41,. The ultimate position of the mechanism isillustrated in Fig. 4, where the parts are shown ready for their returnex- 'Ihe operation of the mechanism upon its return excursion will beapparent from the foregoing description and need not be traced. p

Vhile I have herein set forth and shown in some detail a specificembodiment of my invention capable of accomplishing the results setforth and in its specific construction containing invention, I do notdesire to be understood as limiting myself to such construction alone,as it will be apparent that numerous changes might be made in theparticular embodiment of my invention without departing from the spiritand scope thereof.

Having described my invention, what I claim, and desire to secure byLetters Patent of the United States, is-

l. In combination with a valve having ports and a reciprocating memberarranged to open said ports alternately at opposite ends of its stroke,a valve-retarding device associated with the reciprocating membercomprising a casing providing a cylinder and a duct opening into thecylinder only at its ends, a piston arranged for reciprocation in thecylinder between the duct-openings and two Valves in said duct, eachadapted to permit the free fiow of liquid therethrough in one directionand adjustable to retard its iiow in the other direction.

2. In a dash-pot structure, a stem, a piston having a lost-motionconnection with the stem,

a casing surrounding said piston and a by'- pass way around said piston,arranged to be unaffected by the motion of the piston rela tive to itsstem.

3. In a dash-pot structure, a stem, a piston carried by said stem, acasing surrounding said piston provided with a by-pass duct, and a valveStructure in said duct, having two passages therethrough, and comprisinga check member for closing one passage, and a means extending to theexterior of the casing for adjusting the size of the other passage.

4. In a dash-pot structure., a stem, a piston having a lost motionconnection with said stem, a casing surrounding said piston, and aplurality of by-pass ways around said piston, arranged to affordpassages around said piston at different points in its range ofmovement.

5. In a dash-pot construction, a piston, a 60 casing wherein said pistontravels, a by-pass around said piston, and a valve in said by-pass, saidvalve having two passages therethrough, and comprising an adjustablemember for regulating the size of one of said passages, and a 65check-valve member for closing the other passage in one direction only.

6. In a dash-pot structure, in combination',

a liquid-reservoir, a dash-pot cylinder, a stem extending longitudinallyinto said cylinder, a 70 piston carried by said stem, a by-pass aroundsaid piston, and a passage effecting communication between said by-passand the reservoir.

In testimony that I claim the foregoing as my own I affix my signaturein presence of two 75 witnesses.

HUGH PERRONET THOMPSON. In presence of- GEO. T. MAY, J r., MARY F.ALLEN.

